删除数据库中的一条数据

<%@ WebHandler Language="C#" Class="List" %>

using System;
using System.Web;


using System.Data;
using System.Data.SqlClient;
using System.Text;
using System.IO;

public class List : IHttpHandler {
    
    public void ProcessRequest (HttpContext context) {
        //context.Response.ContentType = "text/plain";
        //context.Response.Write("Hello World");
        DataTable dt = LoadData();
        StringBuilder sb = new StringBuilder("<table style = \"border:1px\">");
        foreach(DataRow dr in dt.Rows)
        {
            sb.Append("<tr>");
            sb.Append("<td>"+ dr[0]+"</td>");
            sb.Append("<td>"+ dr[1]+"</td>");
            sb.Append("<td>"+ dr[2]+"</td>");
            sb.Append("<td><a href='del.ashx?id="+dr[0].ToString()+"'>删除</a></td>");
            sb.Append("</tr>");
        }
        sb.Append("</table>");
        string strPath = context.Server.MapPath("./HtmlModel.htm");
        string strHtml = File.ReadAllText(strPath);
        strHtml= strHtml.Replace("@title","欢迎查看学生列表页");

        strHtml= strHtml.Replace("@body", sb.ToString());
        context.Response.Write(strHtml);
    }

    private DataTable LoadData()
    {
        DataTable dt = null;
        try
        {
            SqlConnection conn = new SqlConnection("Data Source=PC--20130405SCI\\YAOSIR;Initial Catalog=Clients;User ID= sa;Password=123456");

            conn.Open();
            SqlCommand cmd = new SqlCommand();
           
                cmd.CommandText = "Select * from OrderClient";

                cmd.Connection = conn;
                SqlDataReader dr = cmd.ExecuteReader();
                    //SqlDataAdapter da = new SqlDataAdapter(selectStr,conn);
                dt = new DataTable();
                dt.Load(dr);

            
            //string sqlStr = "Select * from OrderClient";
            //SqlDataAdapter da = new SqlDataAdapter(sqlStr, conn);
            //dt = new DataTable();
            //da.Fill(dt);
        }
        catch (Exception e )
        {
            
            throw new Exception("执行出现异常...");
        }
        
        return dt;
    }
 
    public bool IsReusable {
        get {
            return false;
        }
    }

}

点击“删除”跳转到del.ashx页面

<%@ WebHandler Language="C#" Class="del" %>

using System;
using System.Web;
using System.Data;
using System.Data.SqlClient;

public class del : IHttpHandler {
    
    public void ProcessRequest (HttpContext context) {
        //context.Response.ContentType = "text/plain";
        //context.Response.Write("Hello World");
        string sid = context.Request.QueryString["id"];
        if (sid != null)
        {
            int ID = -1;
            if (int.TryParse(sid, out ID))
            {
                if (DoDel(ID))
                {
                    context.Response.Write("删除成功！");
                }
                else
                {
                    context.Response.Write("删除失败！");
                }
            }
            else
            {
                context.Response.Write("主键转换失败....");
            }
        }
        else
        {
            context.Response.Write("未获取主键值！"); 
        }
    }
    private bool DoDel(int id)
    {
        string connStr = "Data Source=PC--20130405SCI\\YAOSIR;Initial Catalog=Clients;User ID= sa;Password=123456";
        SqlConnection conn = new SqlConnection(connStr);
        conn.Open();
        string sqlStr = "delete from OrderClient where ClientID = @sid";
        SqlCommand cmd = new SqlCommand(sqlStr, conn);
        SqlParameter par = new SqlParameter("@sid",id);
        cmd.Parameters.Add(par);
        int result = cmd.ExecuteNonQuery();
        
        return result>0; 
    }
 
    public bool IsReusable {
        get {
            return false;
        }
    }

}